a. Field of Invention
The invention relates generally to vehicle structural design for noise control, and more particularly, to the structural design of vehicle rear doors and their related components for minimizing wind generated noise.
b. Description of Related Art
As is known in the art, automobiles include a variety of interior and exterior structural components whose design is governed by a variety of performance factors, some of which are related to minimizing noise within the occupant compartment. Such noise related performance factors themselves are limited in their application due to aesthetic or functional considerations. For example, whereas vents and other such components may be provided for minimizing wind related noise when one or more windows are opened, such components may however be undesirable from an aesthetics viewpoint.
One such area of wind related noise includes noise generated when automobile front windows are closed, with the rear windows being open. The noise generated in such a condition is often referred to as wind throb or “helicopter” noise, and is especially prevalent in sport utility vehicles (SUVs). While this noise can be reduced by partially or fully opening the front windows for thus providing adequate venting for the vehicle occupant compartment, many drivers are unaware of the source, much less the remedy for such noise. Moreover, in certain conditions where it is desirable for an operator to have the front windows fully closed with the rear windows opened, venting of the passenger compartment may not be an option.
In the art, as disclosed for example in U.S. Pat. No. 6,729,674 to Davis and U.S. Publication No. 2006/0059799 A1 to Zimmer, there exists a variety of techniques and devices for minimizing wind generated noise.
Referring to FIG. 1 of Davis, there is disclosed a window assembly including movable window (18) retractable into vehicle door (12), with window (18) slidably engaging dividing member (22). A rail or guide member (24) slidably engages a channel or track (22a) of dividing member (22). As shown in FIGS. 1, 2, 8A and 8B, this allows fixed window panel (16) and movable window panel (18) to be substantially flushed-mounted relative to one another, such that the outer surface of both window panels form a continuous planar surface. The absence of the protruding edge of the dividing bar prevents development of additional turbulence and minimizes noise, in accordance with the purpose of the Davis invention (see Col. 2:35-41; Col. 3:35-41; Col. 4:39 to Col. 5:11).
While the movable window (18) of Davis affects wind generated noise within the vehicle occupant compartment, the Davis assembly however has several drawbacks from an aesthetics and functional standpoint. From an aesthetics standpoint, the Davis assembly clearly includes two separate windows that alter the vehicle appearance when the windows are opened or closed. From a functional standpoint, the Davis assembly requires the manufacture of separate windows and related components, thus significantly adding to the overall cost of the assembly. Moreover, the Davis assembly does not allow the overall window opening to be used due to the fixed and necessary requirement of dividing member (22).
In another such device for minimizing wind generated noise, Zimmer discloses in FIGS. 3 and 4 thereof an invisible division bar assembly (80). The division bar spans the interface between movable window (30) and fixed window (32). The joint between the movable and fixed windows does not extend outwardly beyond the plane defined by the exterior surface of the movable and fixed windows. This flush arrangement reduces issues with respect to wind noise, according to the purpose of the Zimmer invention (see Paragraphs 2, 3, 6, 13 and 24-26).
The invisible division bar assembly of Zimmer is also problematic from a functional standpoint in that the assembly is primarily directed to eliminating turbulence caused by a protruding division bar, and not to the wind throb or “helicopter” noise generated when the rear windows are open with the front windows being closed.
It is therefore desirable to provide a component for minimizing wind related noise, especially, the wind throb or “helicopter” noise generated when the rear windows are open with the front windows being closed, without the design being obtrusive from a manufacturing or aesthetics standpoint. It is also desirable to provide a component for minimizing wind related noise which does not require special manufacturing considerations and is not therefore cost prohibitive.